This invention relates to a small-sized snowmobile and in particular to a small-sized snowmobile having a water-cooled engine for driving it.
A conventional small-sized snowmobile is mostly equipped with an air-cooled engine. However, the air-cooled engine has a poor cooling efficiency and a stable, uniform cooling is not obtained for each part of the engine. Furthermore, the air-cooled engine produces louder noises during the operation. In order to avoid such drawbacks inherent in the air-cooled engine, various attempts have been made to use a water-cooled engine in the small-sized snowmobile. The snowmobile has an engine compartment on the forward end portion whose side view provides a streamline configuration. It is therefore difficult to obtain a space sufficient to mount a radiator upright at the forward end portion of the engine compartment. For this reason, the conventional small-sized snowmobile has, for example, a radiator mounted upright at the rear portion of the engine or at the rear end portion of an engine compartment so as to take air from above and flow the air downward through the radiator. With the small-sized snowmobile of such type, however, air is taken from above the rear end portion of the engine compartment in a manner that air current is forcefully bent through air ducts. As a result, the radiator can not be sufficiently cooled due to a poor air flow efficiency. Furthermore, air resistance is undesirably involved.